DH Blog

Terminology Update: LOINC and LIVD Standards

08/16/2018

John Snyder, NDTR, RDN
Lead Medical Terminologist

Diameter Health Supports LOINC and the LIVD Standard; have you requested a LIVD file from your IVD device vendor?

Meaningful Use Stage II required that all laboratory results be mapped to the Logical Observations Identifiers Names and Codes (LOINC ®) code system. Surprisingly, 4 years after its go-live date, it is estimated that 50% of all laboratory result data continues to be resulted and/or transmitted without an associated LOINC code. To this end, the IVD Industry Connectivity Consortium (IICC) has announced the creation of the LIVD (Pronounced “liv-id”) specification for the digital publication of LOINC codes for in-vitro device (IVD) test results. The file format, currently Microsoft Excel, may be used as-is by IVD software systems to automate the test result to LOINC code mapping between (IVD) devices and Laboratory Information Systems (LIS). Using a manufacturer provided LIVD file, a laboratory can map a test result to the appropriate LOINC code based on the manufacturer’s defined instrument, assay, type of specimen and unit of measure. When using the file as a reference point for mapping to LOINC, the laboratory needs to take into consideration their local configuration of the device to determine the appropriate LOINC code. The LIVD specification was a collaborative effort between the IVD Industry Connectivity Consortium (IICC), IHE Pathology and Laboratory Medicine (PaLM), Regenstrief Center for Biomedical Informatics, the U.S. Centers for Disease Control and Prevention (CDC), and the U.S. Food and Drug Administration (FDA). Several major IVD vendors such as bioMérieux ®, Abbott Laboratories ®, and Roche Diagnostics ® have already adopted the LIVD standard and have or will soon have LIVD content available upon request to their customers. Contact your IVD vendor today to gain access to the LIVD content.

There are two questions implied in this topic. The first question is how often should organizations update to the most recent version of the LOINC code system after it has been made publicly available from Regenstrief? The second and slightly more daunting question is how often should organizations update mappings to LOINC? The answer to these two questions will help your organization proactively curate your LOINC content.

So, how often should a laboratory or healthcare organization update to the most recent version of the LOINC code system? This topic was brought up as part of a discussion on best practices at the December 2015 laboratory LOINC committee meeting. The committee recognized that there are several unintended consequences of the meaningful use regulations specifying a version of LOINC because the rule-makers may not specify a version that doesn’t yet exist. While the Meaningful Use Certification rules do allow for updating to the current version, many organizations may choose not to due to costs and challenges surrounding implementation and maintenance. The committee unanimously voted in favor of recommending that users update to the current version of LOINC within 90 days of its publication. The basis for this recommendation is that each new release of LOINC is an improvement over the last and contains new content that may be required for a laboratory to use in order to keep pace with the healthcare environment. On average, LOINC adds 1800 new terms with each biannual release. It also continues to expand scope of coverage to include new domains such as radiology, clinical documents, and genetics. Delaying the import of updated LOINC content may mean more extensive error logs due to missing content as well as a larger resource effort if only done once every 2 years as opposed to performing these updates as regularly schedule maintenance every 6 months.

Secondly, how often should an organization update their mappings to LOINC? In addition to adding new content with each release, LOINC may change the status of an existing LOINC code to “discouraged” or “deprecated.” By definition, a discouraged code may continue to be used in an existing map but should not be used for new mappings. A deprecated code should not appear in an existing map, nor should it be used in the creation of a new map. To help ease the burden of identifying replacement LOINC codes, LOINC publishes an accessory file of replacement codes (i.e. map_to.csv), which is included with each public release. At minimum, Diameter Health recommends that laboratories and healthcare organizations review their LOINC maps with each public release of the code system and remap any LOINC codes that have undergone a status change from active to either deprecated or discouraged.

The adoption of electronic transitions of care and/or summary of care documents using the HL7 C-CDA specification means that laboratory data isn’t just being resulted to a local healthcare organization or provider and stopping. The advent of these electronic documents means that laboratory data is now flowing outside of any given healthcare organization to any number of receiving organizations, both nationally and internationally. Updating to the most current version of LOINC within 90 days of its publication and actively reviewing maps on a biannual basis for deprecated and discouraged LOINC codes helps ensure that the most current active LOINC content is available for laboratory and associated result content.

What’s all this about Labradors? LOINC Laboratory Order Codes

Laboratorians responsible for mapping laboratory results to LOINC should be aware that a class of LOINC codes named “LABORDERS” exists and could easily cause erroneous mappings. Open the LOINC search webpage and search for “hgb a1c”. In the resulting list you will see the following two entries:

55454-3 | Hemoglobin A1c in Blood (Class: LABORDERS)

41995-2 | Hemoglobin A1c [Mass/volume] in Blood (Class: HEM/BC)

The first LOINC code is one of 27 LOINC codes for individual tests with a term definition that states:

“Created ONLY for ORDERING in response to request from Canada Health Infoway- a national standardization effort. The dashes in this case mean that the ordering provider does not care what property or scale is used in the observation performed in response to this order. LOINC is still pondering details about how this kind of item should be represented. So, the representation might change in the future, but the term will still have the same usage and meaning.”

In the case of LOINC order codes, there are two tell-tale signs that the code being selected should not be used when mapping a laboratory result. the long common name doesn’t contain the result scale (e.g. [Mass/volume]); and the class indicates it is a “Lab order”. However, keep in mind, these two LOINC codes appear together in the search results, making it very easy for a mapper to inadvertently select the code meant for ordering only and use it for mapping a laboratory result. Being aware of nuances like this in LOINC will help to prevent erroneous mappings from being created and transmitted across healthcare organizations.

As of version 2.64, released June 15, 2018, there are only 27 LOINC codes with a class of “LABORDERS”. Given that ONC has expressed an interest in using LOINC for ordering purpose in the future, this number may grow over time. If you have any questions, or would like a list of the 27 LOINC codes discussed, please contact Diameter Health or LOINC.